HG-AFS Determination of Trace Amount of Arsenic in Traditional Chinese Medicines with Microwave Assisted Sample Digestion

HG-AFS was applied to the determination of trace amounts of arsenic in traditional Chinese medicine (TCM), including angelica, salvia, liquorice, panax and astragalus. Samples of TCM was digested with mixed solution of HNO3-H2O2 (3+1), and the mixture of thiourea and ascorbic acid was added to the sample solution as pre-reductant. Hydrides of As(Ⅲ) were generated from HCl (3+97) solution by reacting with 10 g·L-1 KBH4 solution (dissolved in 20 g·L-1 KOH solution). Flow-rates of 800 mL·min-1 for carrier gas and 800 mL·min-1 for shielding gas were taken in the analysis. Linear relationship between the fluorescence intensity and mass concentration of As found was in the range within 12 μg·L-1, with detection limit (3s/k) of 0.020 μg·L-1. The proposed method was applied to the analysis of hair (GBW 09101), the results obtained were in conformity with the certified values.